DefenceVPN is just the right choice for a VPN.

Installing On Android (OpenVPN)

Step 2. Download and Send .OVPN FilesDownload the .ovpn and CA certificate files for the server you wish to connect to from the server status page. Open the CA certificate and copy the contents inside the .ovpn file like so;

<ca>
CERT_FILE_CONTENT_COMES_HERE
</ca>

After that, email yourself the .ovpn files.

Step 3. Connect to DefenceVPNOpen the OpenVPN connect app, import your .OVPN files that you emailed yourself (this can be done directly from the mail app) or by clicking the import button in the OpenVPN connect app.